The present invention relates to a rigid packaging container for dry or moist foods and other dry or semi-fluid materials, comprising a reclosable, locking, molded fitment device as a closure means. The closure means facilitates easy opening of the container, and can remain open unaided or may otherwise be locked in the open position for ease of removing the material, as in pouring. The closure means may also be locked in the closed position to prevent spillage of the material from within the container. The container may further be adapted as a barrier package for materials sensitive to light, oxygen and other gases while preventing the migration or destruction of flavor components and vitamins from within the container by incorporating a barrier material, fin seal closure elements in the box construction, and a tearable opening means formed by a series of laser cuts that do not penetrate the barrier material.
In response to a need for a package with a reclosable opening, U.S. Pat. No. 3,104,591 (Ahlbor) describes a soft package for cigarettes or similar articles, which is designed to combine certain advantages of both a soft package and a rigid box. The body of the package is made of a thin wrapper or envelope blank. The soft package has a rectangular top end, which includes an adhesively attached cap made from a cap blank consisting of a more rigid material than the thin wrapper which forms the package body. According to the patent, the cap blank has incisions to form a lid opening when the cap is attached to the package body, and includes a fold line along the top of the opening that provides a hinged lid. The cap blank is secured, via adhesive zones, to the top end of the package so as to form a cap over half of the top end. The package body beneath the attached cap is perforated with tearing lines that allow the portion of the wrapper attached beneath the lid opening to be torn away and swung upwardly with the lid when it is opened. Although this patent recognized the need for a package with a reclosable opening, a need for a rigid container with a reclosable locking feature that was at the same time suitable for packaging delicate materials, such as flaky foods, remained evident in the art.
Rigid, reclosable paperboard containers suitable for packaging dry materials have more recently been developed for packaging food materials. For example, U.S. Pat. Nos. 3,765,593, 4,421,236, 4,768,703 and 5,911,359 disclose box containers having reclosable openings. U.S. Pat. No. 3,765,593 (D""Alessio) discloses a tubular cardboard carton having a diagonal flip-top structure that is formed from a single panel blank. The blank is cut and folded to form a front panel having a cutaway edge that is recessed from the edge of the upper end of the box, thereby forming an opening, and a rear panel having an extended tab portion contiguous with its side edge. When the panels are folded to form the carton, the extended tab portion of the rear panel folds over the edge of the opening in the front panel to form an integral side-hinged closure that covers the opening. This type of closure, however, cannot be locked to secure the opening and prevent spillage of the contents from the container, if, for example, the carton is inverted.
U.S. Pat. No. 4,421,236 (Lowe) discloses a carton for packaging cereals or other dry products, which is constructed from a blank having side and end closure flaps that are extensions of the front, rear and end panels of the blank. The reclosable opening is formed by imparting tear lines in a parallel spaced relationship to the upper edges of the front, rear and end panels, score lines in parallel spaced relationship to the tear lines, die cuts at the ends of each tear line, and further having a score line across the top portion, the combination of which integrally forms an upwardly pivotable flap. When the sealed carton is opened along the tear lines and folded back along the score line, the flap forms a pouring spout for dispensing of product from the carton. Lowe provides that the carton may also include a barrier coating or laminate that eliminates the need for a separate liner, and which maintains the freshness or integrity of the product stored in the carton. The disclosed closure means cannot be secured. Additionally, Lowe does not disclose or contemplate maintaining the integrity of the barrier coating or laminate in the unopened carton, since the tear lines in such cartons typically penetrate and therefore compromise the barrier coating or laminate material.
U.S. Pat. No. 4,768,703 (Sosler) discloses a carton having a top cover with a peripherally depending flange that is affixed to the open top end of the carton. Perforation lines around the periphery of the flange that penetrate through the flange as well as the front, rear and end panels of the carton, and a transverse score line in the top panel form a reclosable hinged cover and pour spout. The pour spout is closed by pulling the hinged cover downward over the open top end of the carton. A membrane liner may be separately heat sealed to the open top end of the carton before the top cover is attached. In this regard, after the carton is opened, the membrane liner portion may be pivoted upwardly and outwardly to dispense the carton contents, and the carton may be reclosed by pushing the membrane liner downward over the open top end then closing the hinged cover. Once the carton is opened by tearing along the perforations, it may be locked in open position by orienting the perforations in the flange so that they extend angularly from the opposing edges of the top panel to terminal flange edges in the unopened section of the cover. This closure means is not secure, however, and is susceptible to inadvertent opening and spillage of the carton contents if, for example, the carton is inverted. Moreover, the membrane liner does not provide full barrier protection to the package contents when it is unopened, since the inside of the carton is not completely sealed.
U.S. Pat. No. 5,911,359 (Stone) discloses a one-piece, flip-top carton with a lid formed from the combination of a perforation oriented parallel to the top edge of one end panel, obliquely oriented perforations along the front and rear panels, and at least one horizontal fold line across the closed top end. The carton blank is shaped to include a tabbed portion that, when folded, forms the flip top. This type of closure does not provide secure fastening means. The patent neither mentions nor suggests a means of dealing with the problem of deterioration of the package contents due to exposure to air and moisture.
None of the foregoing references addresses the problem of protecting the contents of the sealed container from exposure to light, oxygen or moisture vapor before it is opened. Other patents, however, have attempted to provide such barrier packaging. U.S. Pat. No. 4,239,150 (Schadowski) discloses a folding carton for leak-proof packaging of liquids having a skived side seam formed by shaving one side of the seam to form a tapered wedge. The wedge is then overlapped beneath the thicker, untapered portion of the seam to form a joint that is then bonded or sealed. The patent mentions that the seam so formed provides high liquid tightness even when the lapped seam is of slight thickness. The carton disclosed by this patent does not include any features to provide hermetic barrier packaging of materials while providing ease of opening, and no mention is made of a reclosable closure.
U.S. Pat. No. 5,101,999 (Robichaud) discloses a closure mechanism for cartons used in liquid packaging, the closure having a base attachable to the top of the carton over a scored area consisting of a first and second perimeter cut, each of which may be serrated or perforated, to permit penetration of an outer polyethylene layer; and a series of half cuts and arc cuts circumscribing a middle cut, which are designed to produce xe2x80x9cbomb bayxe2x80x9d doors when the middle cut is depressed inward by a push-tab or button appended from the inside of the hinged lid of the closure mechanism. The carton may preferably be formed from a laminate having therein a barrier material that is maintained unbroken in advance of opening. The disadvantage of the disclosed closure means is that it does not permit easy opening, as considerable pressure must be exerted on the push-tab to puncture the middle cut and form the xe2x80x9cbomb bayxe2x80x9d doors, and the scored area forming the opening is not maintained external to the carton. Rather, the broken scored area is pushed inward and therefore it cannot be removed from the carton after it is opened. The carton opening so formed is not a completely unobstructed opening, and, as a result, this type of closure cannot efficiently be used to package a pourable non-liquid material.
Most recently, the need for an easy to open barrier carton suitable for packaging non-liquid materials was addressed by U.S. Pat. No. 6,047,883 (Calvert). Calvert describes a bagless barrier paperboard container having a locking, reclosable fitment closure affixed to the top panel in parallel relation to the front and rear panels. The inner contact surface of the container is coated with a polymeric coating that exhibits excellent moisture vapor, oxygen and flavor barrier characteristics. A disadvantage of the Calvert container, however, is that in order to provide easy opening, a peelable sealant closure must be applied to the top fin or gable seal to form an opening means, and the inclusion of this element may compromise the barrier properties.
Accordingly, there is a need evident in the art for a fairly rigid, product-protecting packaging container that can be manufactured with a locking, reclosable fitment or closure means for securing the container opening, whether such closure means is in an open or closed position, while providing excellent barrier properties prior to opening of the container.
These objectives are met by the present invention, which provides a locking reclosable container for packaging pourable non-liquid materials, and a means for packaging such materials. The term xe2x80x9cnon-liquidxe2x80x9d, as used herein means dry or moist non-fluid materials having varying levels of moisture without being of a liquid consistency. The container can be easily secured to prevent accidental spillage after it is opened. The locking means is provided by a molded fitment, which is mounted over a removable tearable opening at or near the top of the container. This molded fitment may be locked in the closed position and can, advantageously, remain open unaided or optionally be locked in the open position.
More specifically, the present invention provides a container and methods for providing barrier protection to a packaged non-liquid material, wherein the unopened container provides a hermetically sealed barrier against incursion by the external atmosphere, and blocks the entry of light, oxygen, moisture vapor or other gases, and the escape of flavor components, if such functions are required. This hermetically sealed container is achieved by the combination of several features. First, the container body is formed from a laminated substrate having, as at least one layer thereof, a barrier material that is impermeable to oxygen, moisture vapor or other gases. An additional factor in achieving the barrier protection is the construction of the container body, which is preferably formed using fin seals that are folded flat and sealed against the container body during the forming process, thereby forming a tighter, less gas-permeable seal. The container body is also preferably formed with a skived side seam; however, this element is optional and not required. In addition, the container body suitably includes one or more series of cuts to form an easily tearable and removable opening, while avoiding penetration of the barrier material. The container body having these features is fitted with a molded, reclosable locking fitment to secure the opening after the container has been opened. Such a container provides a high level of barrier protection without the need for a separate packaging means, such as a polymer-based bag, inside the container. Accordingly, the container of the invention is suitable for packaging pourable non-liquid materials, such as cereals, pet food or other materials requiring barrier protection, and, in particular, for packaging such materials without using conventional bag-in-box packages.
In one aspect, therefore, the invention comprises a stackable, bagless, reclosable packaging container, comprising a container body in the form of a rigid box, and further comprising a reclosable locking fitment, which is lockable in either the open or closed position. In this regard, the box may be formed from any rigid, foldable substrate, such as a paperboard, plastic or any combination thereof. The box is suitably formed by folding and sealing a pre-cut blank, which may be manufactured in bulk according to means well known in the art. Suitable substrates from which the blank may be constructed include coated or uncoated paperboard, which may include, as a component, bleached or unbleached pulp; and plastics such as polyolefins, polycarbonates, vinyl polymers, polyesters and acrylics; or any combination thereof. Representative of these types of substrates are solid bleached sulfate paperboard (SBS), clay-coated newsback (CCNB), coated solid unbleached sulfate (SUS), multi-ply folding box board or kraft paperboard. To provide the barrier properties that are a desired feature of the present invention, polymeric materials such as polyethylene, polypropylene, metallized polyester, ethylene vinyl alcohol (EVOH) copolymer, nylon, aluminum foil, or any combination thereof are suitably included in the substrate. The barrier material may be selected based on the type and level of barrier protection it contributes to the substrate, and its compatibility with the substrate. For example, the barrier material may be selected from the group consisting of metallized polyester, metallized polypropylene, metallized oriented polypropylene, polyvinylidene chloride (PVDC), ethylene vinyl alcohol (EVOH) copolymer, nylon and aluminum foil. The number, arrangement and placement of the layers may be modified depending on the desired results. It should additionally be recognized that the substrate might, in alternative embodiments, be comprised of a single to layer of material that possesses barrier properties, without being laminated with any additional layers.
The laminated substrate may be formed by extrusion coating, extrusion lamination, adhesive lamination, dry lamination, solvent coating, aqueous coating or combinations thereof. For additional barrier properties, oxygen scavengers or other fillers or additives may be incorporated into one or more layers of the laminate. In certain situations it may be desirable to incorporate antioxidants such as BHT into one or more layers in order to take advantage of the positive effect this is known to have on the shelf life of certain packaged foods.
The barrier layer may also serve as the product contact layer within the container, or, optionally, an additional layer may be included in the substrate as the contact layer. The choice of the contact layer is also determined, in part, by the intended use of the container. For example, where the material to be packaged is of food grade, the contact layer is desirably formed from an approved food-grade material. The laminated substrate may also include one or more layers of other materials, such as tie layers, primer layers or adhesive layers, to increase the adhesion between the other layers.
An example of a suitable laminated substrate for forming a barrier container according to the invention is a 16-point SBS paperboard manufactured by Westvaco Corporation, which may be laminated together with one or more layers of polymeric or barrier-forming materials. The outer surface of the substrate, which forms the outside of the box, may be coated for printing, or it may be left uncoated, depending on the type of substrate used, and the intended application for the container. Conceivably, the inner surface of the substrate may also be modified to allow printing, depending on the desired application.
The blank may be scored with fold lines to provide front, rear and side panels and a sealable flange, which may optionally be skived, for forming a side seam. The blank is further suitably perforated with a series of cuts to form a tearable opening means. The term xe2x80x9cperforatedxe2x80x9d, as used herein, means the formation of a series of cuts of a predetermined size and configuration through at least part of the thickness of the substrate to form a tearable opening that provides easy access to the contents of the container. Preferably, the cuts penetrate one or more layers of the substrate so as to form a tear guide for easy opening and removal of the perforated area, but avoid penetrating the barrier material. Where barrier properties are not required, however, the cuts may perforate the entire thickness of the substrate. The cuts may be made by any suitable means for achieving the desired length depth and configuration. Preferably, where a barrier function is desired, the cuts are made using a laser-cutting means. For example, the substrate may be partially penetrated by light pulses from a 100-800 watt carbon dioxide laser, available, for example, from Laser Machining Inc., to produce tear-guiding cuts that do not compromise the barrier layer of the substrate. The dimensions and spatial orientation of the cuts have also been found to affect the strength of the perforated region and its burst resistance. Suitably, therefore, the laser-cut opening may be formed from linear, jagged or curvilinear cuts of equivalent length or alternating long and short lengths, or combinations thereof, any of which may be in staggered orientation to form a tearable opening.
Suitably, the container of the invention also comprises a molded reclosable locking fitment that includes a frame, configured in dimension and shape to be mounted over the tearable perforated opening, preferably at or near the top to allow for pouring out of the box contents; and an attached fitment lid. The fitment lid can be locked in the closed position, and can remain open without aid of the human hand or any external device, in the open position, in relation to the frame. In this regard, the fitment lid is able to remain open unaided and will not close while the contents of the container are being poured out. In certain preferred embodiments of the invention, for example where the fitment lid is a hinged device, this characteristic may be due, in part, to the fitment and the hinge elements thereof being molded in the open position. As a result, the positive tension that is exerted when the hinge is bent to close the fitment lid is released when the lid is opened, and consequently the lid independently remains in the open position. In one such preferred embodiment, the fitment lid is hingedly attached to the frame, and is of an angular configuration consistent with the shape of the box, such that when the fitment lid is closed, the symmetry of the box is maintained. In this regard, the containers of the invention may be efficiently stacked or boxed for shipment and storage.
The fitment suitably comprises one or more locking mechanisms, which permits the fitment lid to be held in place in either the open or closed position. In a preferred embodiment, such locking mechanisms are each formed from one or more tab elements and correspondingly placed slot elements, such tab elements being reversibly and lockably engaged with the correspondingly placed slot elements when the lid is in either the open or closed position. For example, the fitment may comprise a first locking means having a first tab element integrally formed with and appending outwardly from the lower edge of the frame in direct relation to a first slot element near the lower edge of the lid, to provide a closure means when the first slot element is lowered over the first tab element and pressure is applied to the lower lid edge. When pressure is applied, said first slot element lockably engages the first tab element, thereby securely closing the fitment lid.
Such a fitment also optionally comprises a second locking means having an integrally formed second tab element at the upper edge of the frame, positioned in corresponding relation to a second slot element that is approximately equidistantly placed along the hinged upper edge of the lid, such that when the fitment lid is closed, the second slot element is positioned parallel to the upper edge of the frame, directly above, but not engaging, the second tab element. This combination of the second tab element and second slot element further provides a locking means when the fitment lid is fully opened such that the top of the fitment lid is parallel and planar with the top of the box, to provide full engagement of the second tab element within the second slot element and thereby preventing movement of the fitment lid.
While the fitment should be of a type that is lockable in the closed position, and further is capable of remaining open unaided or is otherwise lockable in the open position, a range of suitable fitments may be employed. The fitment itself may be manufactured from any suitable material compatible with the materials to be packaged, which is resilient enough to provide repeated opening and closure of the container, and which, preferably, is also economical to produce. Useful materials for this purpose may be selected from a wide range of moldable resins that can be formed according to a suitable molding procedure, such as injection molding or thermoforming. For example, the fitment may be molded from a material such as polypropylene (PP), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), polyester or polystyrene. The parameters required for such a molding process and for producing fitments of various dimensions may be readily determined by one of ordinary skill in the art.
Suitably, the packaging container of the invention comprises a container body in the form of a rigid box. The box is constructed of a laminated material comprising at least one layer of a barrier material, wherein the at least one layer of barrier material is not perforated, and further includes one or more fin seals and optionally a side seam that may be skived as the means of seam closure. The fin seals are tighter and less susceptible to air and moisture vapor permeation than other conventionally known seals, such as gable seals, and, in this regard, the barrier properties of the packaging container are improved. Fin seals may secure any of the top, bottom or sides of the box. Preferably, top and bottom fin seals are formed in combination with an overlapped side seam that is advantageously skived to form a tighter seal. The combination of the top and bottom fin seals and the skived side seam, in addition to the unperforated barrier material present in the substrate, form a hermetically sealed container that is also easy to open, and which is therefore highly effective for barrier packaging applications.
Notwithstanding the foregoing description, it is to be understood that in a broader aspect the container of the invention comprises a box made of a substrate that may not necessarily possess barrier properties, but which includes a molded reclosable locking fitment having at least one locking means and any combination of fin seals, a skived side seam and a removable perforated opening.
In yet another aspect, the invention comprises a method of packaging materials that are susceptible to light, oxygen, moisture vapor or other gases to extend the shelf life thereof, comprising:
a) forming a box from a laminated substrate having at least one layer of a barrier material in a process comprising:
(i) cutting a blank from the laminated substrate;
(ii) scoring said blank with fold lines to form front, rear and side panels and a flange;
(iii) laser-cutting a series of cuts to form a tearable perforated opening on the surface of the blank, wherein the cuts do not penetrate the barrier material;
(iv) folding the blank along said fold lines, optionally skiving the flange and affixing the outer surface of the flange to the inner surface of the rear panel to form a side seam; and
(v) fin sealing one end of the package to form a box;
b) filling the box with a non-liquid material requiring protection from light, oxygen or moisture vapor;
c) fin-sealing the other end of the box; and
d) affixing a reclosable locking fitment over the tearable perforated opening.